bantu jawab no.28-30 ya yg bisa. makasih

28. 4x3 /2 x 2 = 12
8x3 = 24
8x4 = 32
8x5 = 40
dijumlh smua (12+24+32+40)= 108

30. d1 x d2/2
40 x 30 /2 x 50 = 30.000cm
liter = dm^3
30.000cm = 30liter